Hollow glass article



March 26, 1940. R.-w. KELL HOLLOW GLASS ARTICLE riginal Filed Aug. 12,1937 FIG. 2.

*CQ ATTORNEYS.

Patented Mar. 26, 1940 UNITED STATES aiemse noLLow GLASS ARTICLE RaymondW. Kell, Charleroi, Pa., assignor` to Corning Glass Works, Corning, N.Y., a corporation of New York Original application August 12, 1937,Serial No.

Divided and this application November 3, 1938, .Serial- No. 238,611

3 Claims. (Cl. 'l2-41) This invention relates to hollow glass articles,

as for example building blocks such as are now being used in increasingamounts in the construction of interior and exterior walls, partitionsand roofs, andfor other structures and parts of them, and hasparticularly to do with such blocks or other glass articles made byfirst forming parts of them, and then fusing the parts to each other.

Heretofore in the manufacture of hollow glass building blocks it hasbeen proposed to press form the parts of a hollow glass block, usuallyin halves, heat the meeting edges of these parts, and stick the plasticmeeting edges of the parts together under pressure to form a hollowblock. I have found, however, that in heating the continuous meetingedges of hollow block parts the heat tends to concentrate at the outercomers or portions of the edges. The result is that the bead formed whenthe edges of the parts are pressed together is largest at the outside ofthe block which is often undesirable. Furthermore, the inside corners orportions of the meeting edges of the blocks may even after prolongedheating with the usual ring burner'be so cool that the parts can not bepressed together to form a good tight joint. Again, the heated air andhot gases of combustion must escape'from the inside of the parts beingheated with the result thatthe portions of the meeting edges adjacentthe region of escape of the gases are cooled by the passing gases or areimproperly heated due to deflection of the heating flames with theresult that relatively cool spots are found in the meeting edges whichdo not seal satisfactorily.

It has been proposed, likewise, to dip the edges of the preformed blockparts to be engaged into molten metal and lto thereafter stick the edgestogether and allow the metal to solidify. vThis procedure involves extramanufacturing steps and material and results at best in the formation ofa seal of lower strength than the glass itself. Due to thecharacteristics of the metal and the method by which the seal is madecrystallization of the metal usually occurs to a greater or less extentand an air-tight block is seldom. obtained.

Objects of my invention are to avoid and overcome the foregoing andother objections by the provision of improved sealed articles of hollowglass, as for example building blocks, having smooth external walls anda strong fused glass seal with substantially no external burr, and whicharticles may be efficiently and economically formed. Y

The invention may be best explained by reference to the accompanyingdrawing. in which Fig.

1 is a perspective-view. partly broken away. of a building blockembodying the principles of my invention; Fig. 2 is a fragmentarysectional view,

on a larger scale, of the fused joint of the glass parts forming thearticle; and Fig. 3 is a fragmentary sectional view of a block formed byprior processes.

While as abovev indicated I contemplate form ing various hollow glassarticles from preformed parts, my invention particularly contemplatesthe manufacture of hollow-building blocks and ac cordingly has been-vsoillustrated and will be so described.

A typical block of hollow glass embodying the principles of myinvention, indicated generally by the letter G and shown in Figs. l and2, includes preformed complementa] parts G'G'.v Each tion. The use ofsuch a burner alone inevitably results in uneven` heating of the meetingedges,

as previously explained, the outer portion usually being considerablyhotter than the inner portion`l as well as varying in temperature frompoint to point about the circumference. When sections heated in thismanner'are pressed together to form a sealed hollow body,A acertainamount of upsetting of the edges occurs, the soft hot glass beingdisplaced laterally along the plane of the seal. Along the hotter outeredge of the seal the glass is sumciently fluid to vform a smoothsurfaced, well roundedridge, such as shown atV Il in Fig. 3, while theinner'edge is usually so cool that the two corners fail tovfuse togetherand -as forced outwardly leave a sharply reentrant groove, such asshownat lI5 in Fig. 3, while the inner edge is usually so cool that the twocorners fail to fuse together and as forced outwardly leave a sharplyreentrant groove, such as shown at I5 in Fig. 3 at the inner face of theseal.

Studies of the stresses to which glass building units are subjected whenassembled into walls have established that the point of maximum and areaugmented by the reduced pressure usually existing within the block. Inthe case of a seal such as shown in Fig. 3, two service weaknessesexist. Loading stresses tend to be concentrated by the external ridge i4formed along the seal and the inner face, placed in tension by thesestresses, contains the groove I5 at the point where the tensile stresseswill normally be greatest. It is well known that stresses tend toconcentrate and multiply about a nick ork flaw in a stressed surfacematerially reducing its inherent strength. A groove, such as l5, acts inthis same manner and results in lowering the strength of the blockmaterially below what might be expected from its wall thicknesses.

The present invention eliminates the faults of prior art structures byproviding a block having little or no external ridge |`6 (Fig. 2) toconcentrate loading stresses on the seal and the ma- `jority of theglass in the region of the seal is displaced inwardly forming arelatively large smooth ridge Il having no trace of a groove along theline of theseal.

Various types of apparatus ranging from hand tools to automatic pressesand handling equipment may be employed to form the blocks containing thefeatures of the present invention. However, a convenient and preferableapparatus and method for making the articles of my invention aredisclosed and claimed in my copending application Serial No. 158,732 ofwhich this application is a division.

A feature of the manufacture of hollow glass articles with the apparatusand method disclosed in my parent application is to remove the productsof combustion from the interior of the glass parts G' during and evenafter heating. When, as in prior practice, the products of combustion orother hot gases are not removed from within the burner and the glassparts, 'it is impossible to prevent the gases from either blowingoutwardly over the entire circumferenceA of the piece or channelingthrough the ring of heating flame at localized points. If some partionof the ring of heating flame provided by the burner is slightly thinneror weaker than the rest, the hot gases at the inside of the glass partspour through this portion of the flame and bend it away from engagementwith the glass edge to be heated. Thus one portion of the edge of theglass part being heated may not be heated at all so that the glass partscan not be properly fused together. Where the burner flame is uniformthe hot gases bend the entire ring 0f flame outwardly so that theoutside corners of the meeting edges of the glass parts are most highlyheated and the inside corners are relatively cool. When parts heated inthis manner are joined together seals of the type shown in Fig. 3 areproduced for the reasons given above.

By controlling the amount of gas withdrawn from the interior of theburner and glass parts, the engagement between the burner llames and theedges of the parts can be varied. When a considerable amount of gas iswithdrawn the burner flames are bent slightly inwardly so that theinside corners of the edges of theglass parts are heated to the greatestextent. This is often desirable and is in fact the preferred manner ofmaking the articles of the present invention for the reason that inpressing or fusing the parts or halves of the block together, little orno bead or burr is desired on the outside of the block. When so heatedthe customary pressing together of the heated edges of the anges tendsto dis-I place the softer glass which being mainly at the inside of theline of joinder forms a bead or burr largely on the inside of the block.Withdrawal of a lesser amount of gas will direct the flame squarelyagainst the edge of the flange heating' both inside and outside cornersuniformly. Furthermore, channeling out of the flame as heretoforedescribed is eliminated in all cases by the controlled withdrawal of thehot gases within the parts and the meeting edges are uniformly heatedcircumferentially.

The concentration of heat on the inner edges of the flanges l2, in thepreferred manner just explained, produces the burr formation-heretoforeparticularly described, i. e., the heavy burr I1 on the inside of theblock and substantially no burr, or only -a very small burr IB, on theoutside of the block. While the above-described technique is preferreddue to certain inherent advantages, articles formed according to myinvention may be made by uniformly heating the sections, joining themtogether and mechanically displacingthe glass of the seal inwardlyduring or after the joining operation.

It will be recognized that the objects of my invention have beenattained and that I provide an improved sealed article of hollow glasshaving new and useful structural characteristics. The articles areimproved in appearance, sound and strong in structure, and economicallymade. When laid up into a wall an even pressure is exerted over theentire mortar-contacting faces and localized stresses in the blockstructure are reduced to a minimum lessening the danger of failure inservice.

While in accordance with the patent statutes my invention has beendescribed and illustrated in detail, it should be appreciated that myinvention is not limited thereto or thereby, but is dened in theappended claims. -I claim:

1. An hermetically sealed hollow glass building unit adapted to beassembled in a masonry structure comprising preformed complemental glassparts integrally fused together in the mortar-contacting faces of saidunit, said mortarcontacting faces being substantially smooth along theline of joinder, and a continuously convex, abnormally heavy burr ofglass extending along the line of joinder on the inside of the block. 2.An hermetically sealed hollow glass building unit adapted to beassembled in a masonry structure comprising preformed glass partsintegrally fused together in the mortar-contacting faces of said unit,and characterized by an abnormally large continuously convex burr ofglass on the inside of the block along the line of joinder and anabnormally small continuously convex burr of glass on the outside of theblock at the line of joinder.

3. An hermetically sealed hollow glass building unit adapted to beassembled in a masonry structure comprising preformed glass partsintegrally fused together in the mortar-contacting faces of said unit,and characterized by a relatively large smooth burr of glass on theinside of the block along the line.of joinder and a smaller smooth burrof glass on the outside of the block at the line of joinder, thecombined thickness of the walls and burrs being greatest along thecenter line of the burrs.

RAYMOND W. KELL.

